refactor(solver/icp.cc): Document Icp::EvaluateBox
refactor(solver/icp.cc): Document Icp::EvaluateBox

soonho-tri/dreal4,dreal/dreal4,soonho-tri/dreal4,dreal/dreal4,soonho-tri/dreal4,dreal/dreal4,dreal/dreal4,soonho-tri/dreal4